1. Field of the Invention
The present invention relates to an inductor-less local oscillator buffer implementable on a single-chip CMOS Personal Handy-Phone System (PHS) cellphone.
2. Related Art
The Personal Handy-Phone System (PHS) is a popular mobile network system of cells currently used in urbanized areas of China, Taiwan, and Vietnam. PHS cells are relatively small (e.g. on the order of 10-100 meters) and require relatively low power base stations (e.g. 500 mW). Currently, PHS operates in the 1880-1930 MHz frequency band.
One problem associated with a PHS cellphone receiver is that much of the power budgeted for the receiver is expended in its mixers. Another problem associated with a PHS cellphone receiver is that the local oscillator (LO) buffers providing I and Q signals to the mixers typically include inductors and coupling capacitors, both of which take significant space, for example die area. Therefore, a need arises for a cellphone implementation that can reduce the power budget for its mixers and minimize the footprint of its LO buffers.